Neurophisiology

    Cards (163)

    • What is the role of the sodium pump?
      Maintaining ion gradients
    • Which ion primarily sets the membrane potential?
      Potassium
    • What happens when the membrane potential becomes more negative?
      Hyperpolarization
    • What happens when the membrane potential becomes less negative?
      Depolarization
    • What does the impermeability of the plasma membrane to ions enable cells to do?
      Establish large ion concentration differences
    • What is the plasma membrane's permeability to ions?
      Impermeable
    • Is Na+Na^+ more concentrated inside or outside the cell?

      Outside
    • Is K+K^+ more concentrated inside or outside the cell?

      Inside
    • Is Ca2+Ca^{2+} more concentrated inside or outside the cell?

      Outside
    • Why are ion concentrations across the cell membrane critical?
      For neuronal signalling
    • Is ClCl^- more concentrated inside or outside the cell?

      Outside
    • How are ion concentration differences generated across the cell membrane?
      Low permeability, ion channels, sodium-potassium pumps
    • Why are K+K^+ and Na+Na^+ differences critical?

      Generate resting and action potentials
    • What forms ion channels?
      Proteins spanning the cell membrane
    • What characteristic determines ion channel selectivity?
      Ion selective pores
    • When do ions move through ion channels?
      When the channels are open
    • What is the function of leaky potassium channels?
      Set the resting potential of the cell
    • What are ion channels that are always open called?
      Leaky channels
    • What stimuli can cause normally closed ion channels to open?
      Voltage, neurotransmitter, stretch, pain, light
    • What are voltage-gated sodium and potassium channels responsible for?
      The action potential
    • What do voltage-gated calcium channels trigger?
      Neurotransmitter release at synapses
    • What are ligand-gated ion channels responsible for?
      Synaptic transmission
    • What is the function of the sodium-potassium pump?
      Transports Na+Na^+ out and K+K^+ in
    • What energy source does the sodium-potassium pump require?
      ATP
    • What gradients does the sodium-potassium pump generate?
      Na+Na^+ and K+K^+ concentration gradients
    • Why is low membrane permeability important for the sodium-potassium pump?
      To minimize energy expenditure
    • Why does the neuron need to work hard to maintain K+K^+ inside?

      To maintain ion concentration gradients
    • Does the Na+Na^+/K+/K^+ pump generate the RMP or action potential?

      No
    • What does the Na+Na^+/K+/K^+ pump generate that is essential for neuronal activity?

      Na+Na^+ and K+K^+ concentration gradients
    • Why does the brain need a constant supply of glucose and oxygen?
      To fuel the pumps
    • What is the clinical connection of ischemia?
      Stroke
    • What does lack of oxygen cause in neurons?
      Failure of Na+Na^+/K+/K^+ pumps
    • What do neurons lose due to the failure of Na+Na^+/K+/K^+ pumps?

      Ion gradients
    • What is the consequence of losing ion gradients?
      Loss of neuronal activity
    • What sets the Resting Membrane Potential (RMP)?
      K+K^+ concentration gradient
    • What is the ultimate consequence of the loss of neuronal activity due to ischemia?
      Brain death
    • How does K+K^+ move out of the cell?

      Down its concentration gradient
    • What charge does the inside of the cell become as K+K^+ moves out?

      More negative
    • Is the K+K^+ leak large or small?

      Small
    • What would happen if the K+K^+ leak were large?

      Concentration gradient would be lost